1. Field of the Invention
The present invention relates to a gear crank apparatus for a bicycle having a boss connected to a crank axle, a chainwheel supporting member formed integral with the boss, and a crank extending from the boss.
2. Description of the Related Art
A conventional gear crank apparatus as noted above is disclosed in Japanese utility model application laid open under No. 1977-112055, for example. This apparatus has a boss projecting a considerable amount axially outwardly from chainwheels attached to the apparatus.
Such a conventional apparatus has a disadvantage that, when a pedaling foot slips inwardly in the lower part of pedaling movement, the tiptoe, heel or ankle approaches and could contact the boss of the gear crank apparatus depending on position of the crank. Even where the shoe is fixed to the pedal by means of a cleat, play is allowed in the engagement between shoe and pedal. It is therefore possible that the tiptoe or heel swing toward the boss and contact the boss or adjacent parts.